After completion of the fabrication process of an integrated circuit (IC) device, contact pads are formed over a topmost inter metal dielectric (IMD) and for use in wire bonding or flip-chip bonding. In a flip-chip scale packaging process, a conductive bump is formed to establish an electrical connection between a contact pad and a substrate or a lead frame of the package. In order to fulfill market demands toward increased functionality and decreased manufacturing cost, a wafer-level chip scale packaging (WLCSP) process is introduced by forming a post passivation interconnect (PPI) and/or an under bump metallurgy (UBM) structure over the contact pad. The wafer is sawed into dies to be bonded to a printed circuit board (PCB), in some instances.